Bioavailability
The bioavailability of a medicine measures the quantity of the medicine that is absorbed and made available to exert therapeutic effects on the body.
A medicine administered intravenously will have a bioavailability equal to 100%, as, entering directly into the bloodstream, it will be immediately available to organs and tissues, while medicines administered using other routes (e.g: orally) will have a lower bioavailability value because of partial absorption.